Set of bristles for a brush



FIG. 1 is a perspective view of a set of bristles for a brush, with the broken lines showing a brush head being for illustrative purposes only and forming no part of the claimed design;

FIG. 2 is a top plan view;

FIG. 3 is a right side view, the left side being a mirror image;

FIG. 4 is a bottom plan view;

FIG. 5 is a front elevational view; and,

FIG. 6 is a rear elevational view. 

The ornamental design for a set of bristles for a brush, as shown and described. 